[J.Kissel, T.Mistry]
After the calibration measurement were complete, I went to the X end and powered on and off the NCAL optical encoder system in 20 intervals. The interferometer was in Nominal Low Noise (NLN) at the after the calibration measurements. The motivation of this was to investigate whether the encoder would cause glitches and having known on and off times within the same lock stretch may indicate if this is the case. The first figure attached shows the encoder signal from the channel H1:CAL-NCALX_ENCODER_VELOCITY_OUT_DQ. When the encoder system is powered off, the channel measures 80 +/-1 DAC counts. When the encoder system is turned on, the channels measures 6932 +/-1 (approx 4V). A follow up invesitgation, in addition with investigation from LHO alogs 53503,53441 and 53396. A time log of the activities as taken by J.Kissel are as follows:
1258926919 NLN (Timesh arriving at end station, Jenne feedforward off time stops, Robert still somewhere in/around the YVEA with Wifi and phones ON doing camera recordings of test mass glint, wind fence crews are driving around at EY, audible within the YVEA).
21:55:01 UTC
1258927033 Timesh calls for first go in
21:56:55 UTC
1258927169 +/-15V power supply to mini-field rack Flipped ON. Begin first 20 minutes of ON data.
21:58:59 UTC
(XVEA Lights were left ON)
1258927372 lights OFF now
22:02:34 UTC
1258928389 Timesh begins to head in to turn off NCAL power supply (with lights remaining off)
22:19:31 UTC
1258928508 power supply flipped OFF
22:21:30 UTC
1258928589 Timesh calls back to say he's done turning OFF NCAL.
1258929539 Timesh heads back in to turn NCAL ON
1258929649 NCAL powered ON
22:40:31 UTC
1258930068
22:47:30 UTC
Keita OKs leaving the NCAL ON, as long as we are committed to showing that it doesn't matter.
Timesh goes in to garb room to clean up.
1258930168 Timesh leaves EX
1258930425 IFO handed over to Robert for his tests.
In case it wasn't clear from Timesh's entry: We have left the NCAL system *powered ON,* but not spinning. The data was supremely glitchy today, in general, because if the current wind storm. Thus, it was difficult to make any sound conclusions about whether we were able to reproduce the elevated glitch rate that was reported previously when the NCAL system was similarly powered on, but not spinning (see LHO aLOG 53396). So, we're leaving it powered on but not spinning for a few days to (a) hopefully get some data while the environment is more typical (i.e. quiet) (b) gather days-long stretches of data to be sure leaving it powered on doesn't adversely affect the CW search group. If exonerated, then we don't have to drive to the end station every time we want to use the thing. Stay tuned!
See LHO aLOG 53666 for a first look at this data using Fscans. Further study is needed, but the first look indicates some additional lines or increased line artifacts around this time.